Hi, the example you quoted is absolutely fine. Let me give you my example: One letter I provided was from Ex Chief Oprations Manager Railways. IT is just a one segment of operations in Railways the other segments were transportation, telecommunication etc. So my referee was an over all boss and he sort of talked about impact of my work rather than technical aspect of it. His letter established how and what I changed for good through what I did I.e. to be precise, impact of my software. Then onus was on me to provide technical info on my software which I did through my evidences. So it made the whole picture real HD. And that’s it. I hope this may give you a clue.